Onychiurus fimetarius (L, 1758)
Onychiurus pseudofimetarius Folsom, 1917
Figs 41-43

In my "Index to the Collembola", (p.180) I recorded Folsom's O. pseudofimetarius as a synonym of O. fimetarius L. The figures drawn here are from a specimen labelled cotype of O. pseudofimetarius, USNM No. 20762. Folsom separated his species from fimetarius L. by the extra papilla of SO Ant III and the ventral PSO of the head. Stach (1954) records O. fimetarius with five papillae in SO Ant III and so far as my knowledge goes of this species this is normal structure for this organ. The PAO drawn has 18 vesicles; Stach records 18-24. Two PSO on the ventral surface of the head is normal for fimetarius. It appears, therefore, that Folsom's species is a junior synonym of O. fimetarius L.